Dear friends who have lost weight successfully, what is your experience?

Eat three meals on time every day, mainly vegetarian dishes and chicken and fish, and hardly eat high-carbohydrate staple foods. Calculate the calories strictly with mint software, and control it around 1200 calories. When I was greedy, I ate homemade sugar-free and oil-free popcorn. A large plate of calories is only 50 calories. I didn't exercise for two months and lost weight 15 kg.